Patent GB-1084091-A (GB)
IPC: G01N30/94
Abstract: 1,084,091. Coated sheet material. KODAKPATHE. Aug. 4, 1964 [July 17, 1963; June 15, 1964], No. 30458/64. Headings B1X and B2E. A material comprises a thin layer and a support therefore for use in chromatographic separation of two or more compounds by thin layer chromatography wherein the thin layer is composed of very fine particles of a polymer or of a mixture of very fine particles of a polymer and a porosity adjuvant and/or an ion exchange resin and wherein the thin layer adheres to a flexible support composed of a polymer. The support may be of polyester e.g. polyethylene terephthalate. The porosity adjuvant may be a specific adsorbent e.g. colloidal silica or powdered glass. The thin layer may be composed of (1) from 1 to 10 grams per sq. metre of very fine particles of a watersoluble polyhexamethylene adipamide modified by hexa-methylene sebacamide units or by #-amino-caproic acid units; (2) from 3 to 30 grams per sq. metre of a mixture of very fine particles of a polycarbonate e.g. a high molecular, weight p, p'-bis-(hydroxyphenyl)- 2, 2- propane polycarbonate, and colloidal silica in the ratio of from 10:1.5 to 3:1 by weight; (3) from 0.5 to 2 g. per sq. metre of a mixture of very fine particles of the polyamide referred to above and glass powder in the ratio of from 20 to 40:1 by weight; (4) from 1 to 3 g. per sq. metre of a mixture of very fine particles of polyvinyl alcohol and colloidal silica in the ratio of from 4 to 6:1; (5) a mixture of very fine particles of carboxy methyl cellulose and colloidal silica in the ratio of from 2 to 4:1 by weight; (6) a mixture of very fine particles of the polyamide referred to above and an anion exchange resin in the ratio of from 0.5 to 2:1 by weight. The constituents of the thin layer are homogenized in a mixture of solvents of different volatility and different solvent power for the polymer, of which the solvent of lower solvent power is a poor or non solvent for the polymer and of which the solvent of higher solvent power also has the higher volatility, the homogenised mixture is coated on the polymer support and the solvents are evaporated differentially until the polymer coagulates, there being present in the mixture, before or after homogenisation, a substance which causes the thin layer to adhere to the support or the support having been treated so as to cause the layer to adhere thereto. A method of chromatographic separation by thin layer chromatography comprises depositing a mixture of compounds which are to be separated on the thin layer of the material and is acted on by a carrier liquid moving by capillary action along the thin layer, the constituents of the thin layer being such as to exert a differential restraining effect on the compounds and being inert to the carrier liquid and the support also being inert to the carrier liquid. The compounds may be (a) amino acids, the thin layer being that of (2) above having been, treated with a buffering agent at neutral pH, and the carrier liquid is a mixture of ethanol and water; (b) the anions C1-, Br-and I-, the thin layer being prepared substantially as described in Example 6 or 7 of the Specification, and the carrier liquid is an aqueous solution of sodium nitrate; (c) the cations Ca<SP>++</SP>, Sr<SP>++</SP> and Ba<SP>++</SP>, the thin layer being prepared substantially as described in Example 8 of the Specification and the carrier liquid is an aqueous solution of ammonium lactate.  A method of electrochromatographic separation comprises depositing a mixture of compounds including an ionic compound on the thin layer of the material, the layer is wetted with a liquid which conducts electricity and an electric potential is established in the layer across the mixture so that the ionic compound is displaced in the layer relatively to the other compound.